Many of the world's potable beverages owe their character, complexity and maturity to storage in wood containers. The products are largely, but not exclusively, spirits of distilled ethanols. Ethanolic beverages have long been flavored by contacting the ethanol containing liquid with wood and thereby extracting and reacting certain desirable flavoring components from the wood by leaching into the liquid. Included in this category are whiskies, including Scotch, Irish, bourbon, rye, Canadian, and Australian; and rum, brandy, armagnac, cognac, eau de vie and other distilled beverage bases. Wine, though not distilled, is also often matured in wood. In particular, most of the world's red wines, dessert, or appetizer wines, and some of the white wines, derive their essential characteristics from storage in wood containers. Under United States law certain ethanol beverages are required to have certain minimum periods in contact with wood.
Presently, maturation of these products is accomplished by placing the liquid in wooden casks or barrels known as tight cooperage, where it remains for weeks, months or years depending on the desired level of maturation. Of particular significance is the aging of whiskies and brandies in which years of maturation in contact with wood are required. The essential character of all these products is the result of the chemical changes that occur from contact with and the chemical interaction of their ethanolic and water content to their so-called congeners in the wood. No convenient, alternative technology of maturation has been developed.
Many woods contain flavor agents (congeners) essential and desired for beverage maturation. An extensive listing of woods with favorable characteristics appears in "Some Aspects of the Wooden Container as a Factor in Wine Maturation", chapter 12 of Chemistry of Winemaking, Singleton, V. L. (1974) at 254-275, incorporated herein by reference. All the woods cited may be used in the process disclosed hereinbelow.
Several detriments are associated with current aging processes. The first of these detriments is related to the cost and availability of the prime types and age and species of wood required to produce the best products. The scarcity, the removal of a natural resource, and the high cost of prime grades of wood have caused producers to use inferior grades of wood in many of their products with resulting lack of fullness and richness of flavor in the ethanolic beverage.
In addition to the cost of wood and labor for making barrels, there is the high inventory cost during the multi-year aging process. The ripening inventory must be stored in barrels, usually each containing no more than 180 liters of liquid, in a secure place not subject to extremes of temperature and humidity, lest the barrels leak or burst.
Yet another major detriment associated with current aging practices is the loss of liquid during the aging process, due to evaporative losses from the barrels which may approach or exceed 4% per year, depending upon storage conditions.
These and other detriments could be minimized or removed if currently available, temperature controlled, stainless steel or glass lined reactors could be used to impart the flavoring components of the wood into large batches of liquid in a process where the flavor transfer from the wood to the liquid could be completed in a matter of hours or days rather than months or years.
Because of the tremendous benefits that could be obtained by avoiding the use of long term barrel aging, there have been significant attempts made over a long period of time to find alternative methods of "aging", "maturing" or "mellowing" the flavor of the ethanolic beverage. For example, there have been attempts to load the liquid with wood chips of various sizes and of various kinds of wood. These methods have however not been successful because the liquid extracts undesirable components along with an insufficient level of desirable components.
Later attempts involved various wood particle pretreatments, such as charring, weathering or boiling the wood chips in water prior to use or combinations of these procedures. None of these methods met with success because of the unbalanced flavor and congener characteristics. A more recent variation on these attempts to circumvent the detriments associated with long term aging in wood barrels is described in Howell et al., U.S. Pat. No. 5,102,675. Howell et al. pretreats wood particles destined to flavor wine by combining a toasting procedure precceded or followed by soaking in water or a weak (less than 10%) aqueous ethanol solution. However, wood particles treated in the described method only partially solve the problem since aging of the wine in contact with the wood particles for at least three or preferrably six months is still required.
Thus, there exists a continuing need to find an alternative to the age old maturation process that provides a flavorful beverage, that does not require a substantial period of time, that can be accomplished in standard industrial reactors, that does not entail a substantial loss of product during the manufacturing process, and that is economical.
It is therefore an object of this invention to provide a process for aging that does not require years to accomplish but days. It is an object to provide a process that does not require the skills of a barrel maker. It is an object to provide a process that does not require a wood barrel for aging. It is an object of this invention to render usable large quantities of wood wasted in conventional barrel production. It is another object to provide a process for treating wood to remove undesirable components. It is an object of this invention to provide a process for flavoring aqueous liquids. It is another object of this invention to provide a process that allows easily reproducible standards for quality control and consistent maturation of aqueous food products. Another object of this invention is to provide a process that controls and largely eliminates product loss.
It is a further object of this invention to provide a wood product that can be used to flavor aqueous beverages. It is a further object to provide a series of wood products able to impart different flavor characteristics to aqueous liquids. Another object is to provide a wood product that is easy to ship and use anywhere in the world. It is an object of this invention to multiply the efficiency of congener release and production for a given quantity of wood. Another object is to provide a wood product that may be recycled and used again as a flavor transfer agent for aqueous beverages.
Yet another object is to develop a beverage having improved and commercially acceptable organoleptic qualities. Another object is to provide ethanolic beverages having taste qualities indistinguishable from existing ethanolic beverages. Yet another object is to provide an ethanolic beverage containing novel organoleptic qualities.